Q: I have an area along my side property line where I have tried to plant a few different types of trees/shrubs, and they all seem to die after a couple of years. A row of five hemlocks first died off, one at a time. Then I tried golden Hinoki cypress... 4 or 5 in a row, and after a year or two, they started dying off. I'm not sure what I can do, or how to determine what the problem may be. Any advice?

A: Lots of factors can kill plants, and the only way to nail it down for sure is to closely inspect the plants and the site. It's a lot like medicine. You might be able to make an educated guess with a second-hand clue or two, but it's impossible to say why a "patient" died without an examination.

Back in the good old days, Extension agents sometimes would go to homes to look at plants and offer solutions. And most garden centers had experts who could at least make educated guesses by inspecting specimens customers took in.

These days, people are more on their own. Budget cuts have shrunk Extension staffs, and since consumers voted with their dollars for low-cost box stores, diagnostic services aren't what they used to be either.

I can make a few suggestions based on what you told me about your plants.

One is the quality of the soil. If drainage is poor in that spot, your conifers may have root-rotted. Almost all conifers resent wet feet.

Planting too deep is another issue I see a lot. When trees are planted so that the root flare is underground (where the trunk widens out and transitions into the root system), roots can suffer from lack of oxygen.

Watering is a third crucial element in new plantings. The soil should be consistently damp the whole way to the bottom of the rootball and around the perimeter of it. Too little or too infrequent watering can dry out roots, and if enough of the root system dies from that, the whole plant shuts down.

Soil-borne disease is another possibility that can root-rot conifers. These overwinter in the soil and can kill ensuing plants if they're susceptible to the pathogen.

I wrote a garden column on "plant detective work" that goes into more detail about the many factors worth checking out as well as some specific signs and symptoms and a list of places to help with diagnosis. You can find it here.

The Links and Resources page of my web site also lists even more resources to help track down exact causes of plant problems, including a few web sites where you type in clues and get a possible diagnosis. Click here and scroll down to the heading, "Bugs/Diseases/Plant Problems."

I wish I knew of an easier way, but I can say that the work is worth it so you don't keep wasting money running into the same plant-killing problem. That gets expensive.